Anion Of Ionic Liquid Research Articles

Novel ionic liquid-infused PVA-based anion exchange membranes boosting bioelectricity yield from microbial fuel cells.

The goal of this research is to develop and characterize low-cost NH4I doped polyvinyl alcohol (PVA)-4-ethyl-4-methylmorpholiniumbromide (ionic liquid) anion exchange membranes (AEM) and its application for membrane cathode assembly. Physical characterization like FTIR, POM, and XRD notified the functional groups, basic structure, and amorphosity of the produced membrane, and it was employed in single-chambered microbial fuel cells (sMFCs) as a separator. The membranes in terms of oxygen diffusion, proton conductivity, and ion exchange capabilities were evaluated. PVA-ionic liquid composite membrane had a greater volumetric power density (PD) with a rise in the ionic liquid concentration, owing to lower internal resistance and reduced biofouling. Ionic conductivity also reduces as loading increases over a certain level of concentration. The incorporation of ionic liquid into the membrane had a considerable impact on impedance minimization (an enhancement in anionic conductivity) and biofouling. When MFC was used with a PVA-ionic liquid-based membrane cathode assembly (MCA), the highest PD of 7.98W/m3 was attained which is better than other composite membranes. The MCA surface area boosted the power output. The PVA-ionic liquid composite membrane proved to be a viable alternative to the more costly commercially available MFC membrane. This paper's novelty lies in synthesizing ammonium iodide (NH4I) doped PVA-ionic liquid membrane and further utilizing it as a separator in MFC. Also, this study demonstrates the membrane's potential for enhancing MFC performance, establishing it as a viable alternative to expensive commercial membranes.

Hydration Pattern of Ionic Liquids in the Stabilization of Insulin Dimer: A Computational Perspective

AbstractCholine [Cho]‐based ionic liquids (ILs) are biodegradable and soluble and have shown strong application in the protein stabilization and drug delivery. In this work, the stability of the insulin dimer is investigated in the presence of [Cho]‐based ILs containing three distinct anions (i.e., acetate [OAc], taurate [Tau], and geranate [Ger]). Molecular dynamics (MD) simulations and density functional theory (DFT) calculations explore insulin's stability and structure in the presence of ILs. MD analyses reveal that the insulin dimer is stabilized by non‐covalent interactions, with hydrogen bonds and anions in ILs playing key roles. Among them, [Cho][OAc] ILs show significantly better stabilization than other anions.This is due to the hydration patterns of acetate anion, which can be compared to Hofmeister series and chemical agent effects (i.e., kosmotrope and chaotrope). Further, non‐covalent interactions index and electron density analyses from the atoms‐in‐molecules theory approach are carried out to quantify the strength of non‐covalent interaction in ILs with water clusters (Wn, n = 0–6). Analyses show the significance of water molecules in the stabilization of insulin dimer in the presence of [Cho]‐based ILs. The study elucidates the role of ILs formulation concerning insulin dimers to improve the transdermal and oral drug delivery systems.

Influence of cations and anions of ionic liquids and salts as additives in RP HPLC systems to the analysis of alkaloids on C18 and Polar RP columns

The ionic nature of basic compounds gives rise to broad asymmetrical chromatographic peaks in RP systems containing a mixture of organic modifiers and water as mobile phases. The addition to the mobile phase of a reagent to block the silanol sites such as salts containing chaotropic anions or ILs gives significantly more symmetric peaks and a high resolution of basic analytes. In systems containing the addition of salts or ILs, the retention of ionic analytes is a consequence of the combination of a mixed mechanism that involves chaotropic, ion-exchange, hydrophobic, and ion-pairing interactions. In this work, the influence of salts consisting of various anions and ILs consisting of various cations and anions on the retention and peak symmetry of alkaloids in RP HPLC systems on C18 and Polar RP columns was investigated. The multiple interactions that salts and ILs experience inside the chromatographic system suggest that the alkaloid-suppressing potency should be measured based on the shape of the chromatographic peaks. In order to better understand the retention mechanism, the retention and symmetry of peaks obtained on both stationary phases and in systems containing salts and ILs were compared.

Interplay of aprotic ionic liquids with hydrogen bonded networks in associating aliphatic alcohols

Non-covalent interactions formed by molecules of aliphatic alcohols in the bulk liquid impart tendencies for the molecules to associate through formation of hydrogen bonding. Aprotic ionic liquids (IL) possess a varying potential to interact with the hydrogen-bonded networks. Mixtures of such alcohols and IL then exhibit strongly non-ideal character, propagating to some peculiar thermodynamic properties. In this work, a hierarchy of the interference of 15 aprotic 1-butyl-3-methyl-imidazolium based IL with hydrogen bonds among heptan-3-ol molecules is established based on a series of atomistic molecular-dynamics (MD) simulations and quantum–mechanical (QM) modeling. Structural, spectroscopic, and thermodynamic observables are calculated to illustrate how individual IL anions affect hydrogen bonding among alcohol molecules. While the inorganic halogenated anions interact weakly with the alcohols, oxygenated anions such as acetate or alkyl-phosphates interact very strongly. A special attention is paid to fine-tuning the implementation of the Drude polarizable model and to using ab initio MD at the density-functional theory (DFT) level to provide reference data to develop an optimum setup of the polarizable model. Challenges associated with using the polarizable molecular simulations of hydrogen-bonded networks and with the limited reliability of DFT-MD are highlighted in this work.

The Role of Asymmetry of Perfluoro anion in Ionic Liquids: From Basic Physical Properties to the Application in Lithium Batteries

From the late 1990s, room temperature molten salts composed of stable perfluoro anion became known as ionic liquids and have been widely recognized and applied in various fields of chemistry for almost three decades. Our research focuses on the use of aliphatic quaternary ammonium cations (AQA) as electrolytes for lithium secondary batteries, which possess unique properties of non-volatility, non-flammability and relatively wide electrochemical window that cannot be achieved with conventional electrolytes. To improve battery performance by reducing the internal resistance of the battery system, we investigated various perfluoro anion as shown in Figure 1. From these studies we concluded that the rate characteristics of lithium secondary batteries with ionic liquids depend not only on viscosity, which governs the diffusion of Li+, but also on the chemical structure of the perfluoro anion, which govern the interaction between Li+ and the anions.1)-3) On the other hand, through these studies, we found that the asymmetry of the anion structure 4)-6) and the ether oxygen in the anion side chain7) have significant effects on thermal and transport properties of the ionic liquid, similar to the asymmetry of the cation represented by 1-ethyl-3-methylimidazolium and the ether oxygen in the side chain represented by N,N-dimethyl-N-ethyl-N-(2-methoxyethyl)ammonium. The most striking results are obtained by lithium (fluorosulfonyl) (trifluorosulfonyl) amide (LiFTA)8), which exhibits a relatively low melting point (T m = 100 °C) among the Li salts and has applications in battery electrolytes 8) and unique electrochemical properties9). Here, we would like to show the importance of developing new anion species that give rise to novel ionic liquids and alkali metal salts based on our results.1) H. Matsumoto, Y. Miyazaki, and H. Ishikawa, Japanese Patent Application (1998).2) H. Matsumoto, “Electrochemical window of Room Temperature Ionic Liquids”,Electrochemical Aspects of Ionic Liquids (Ed. H. Ohno), Wiley (2005).3) H. Matsumoto, Recent advances in Ionic Liquids for Lithium Secondary Batteries: Modern Aspects of Electrochemsitry No.58,: Electrolytes for Lithium and Lithium-Ion Batteries, Eds. T. R. Jow, K. Xu, O. Borodin, and M. Ue, chapter 4, Springer, 2014.4) H. Matsumoto, H. Kageyama, and Y. Miyazaki, Chem. Commun., 1726 (2002).5) H. Matsumoto, H. Sakaebe, and K. Tatsumi, J. Power Sources, 146(1–2), 45 (2005).6) H. Matsumoto, N. Terasawa, T. Umecky, S. Tsuzuki, H. Sakaebe, K. Asaka, and K. Tatsumi, Chem. Lett., 37(10), 1020 (2008).7) Terasawa, S. Tsuzuki, T. Umecky, Y. Saito, and H. Matsumoto, Chem. Commun., 46(10), 1730 (2010).8) Kubota, and H. Matsumoto, J. Phys. Chem. C, 117(37), 18829 (2013).9) H. Sano, K. Kubota, Z. Shiroma, S. Kuwabata, and H. Matsumoto, J. Electrochem. Soc., 167(7) 070502 (2019). Figure 1

Ionic Liquid and Plastic Crystal Battery Electrolytes Utilising New Cation and Anion Structures

It is well known that the nature of the cations and anions used to make ionic liquid (IL) electrolytes can have a significant impact on their chemical and physical properties and on their performance in devices, for example when used in lithium or sodium batteries. The same is true for organic ionic plastic crystals (OIPCs); these salts are structurally analogous to ILs, but they are solid at room temperature and display dynamics that can allow their use as solid state electrolytes. However, the structure-property relationships are arguably even less well understood in OIPCs. Furthermore, the addition of different lithium or sodium salts to ILs and OIPCs, to enable their use in lithium or sodium batteries, introduces further complexities in terms of understanding and optimising the thermal, electrochemical and transport properties.To advance the understanding and application of IL and OIPC-based electrolytes it is important to continue to design and investigate new cation and anion structures. For example, we have recently developed new families of IL and OIPC electrolytes using cations such as the hexamethylguanidinium, cyano- or ether-functionalised ammoniums, oxazolidiniums and morpholiniums, in combination with a range of fluorinated and non-fluorinated anions. Furthermore, a new and seldom explored family of materials can be created by tethering the cation and anion together to form zwitterions.This presentation will give an overview of our recent work making new families of non-volatile electrolytes based on ILs, OIPCs and zwitterions and understanding the impact of structure on device performance. Highlights will include the excellent properties and performance imparted by small oxygen-containing cations, and the promising new results using more environmentally friendly, non-fluorinated salts for Li and Na batteries.

Effect of structure and interaction on physicochemical properties of new [Emim][BF3X] complex anion ionic liquids studied by quantum chemistry.

One of the key challenges in the industrial application of ionic liquids (ILs) is their extreme characteristics, such as viscosity, glass transition temperatures, and conductivity. Understanding the relationship between ILs structure and physicochemical property is a crucial aspect of the directed design of ILs with good properties, which is a prerequisite for their successful implementation in industrial processes. In this work, high-level quantum-chemical research with for four pairs ionic liquids, [Emim][X] and [Emim][BF3X] (X = CH3SO3, EtSO4, HSO4, Tos), was performed, to analyze the stable structure, interionic interaction, and charge transfer and provide a new insight into the property variances at the molecular level. The result shows that the overall structural stability of ionic liquids is contributed with hydrogen bonding network between the protons in the C-H and N-H of the cation and oxygen atoms of the anion, as well as fluorine atoms. The nature and strength of the interionic interaction were measured via atoms in molecule analysis and sobEDAw method and results suggested that BF3 could waning interionic interaction of ion pairs. Moreover, a close relation between the binding energies of ion pairs and physicochemical properties was established: the weaker the interionic interaction, the lower is the viscosity and glass transition, and the higher is the conductivity. Quantum chemistry calculations were performed under B3LYP-D3/aug-cc-pVTZ level of DFT functional using the Gaussian 16 package (version C01). The Multiwfn 3.7 program was used to calculate the electrostatic potential, interaction region indicator, the information of bond critical points, core-valence bifurcation index, and ADCH charge. Visualization of structure and the region of interaction were achieved using VESTA and VMD.

Exploring the Influence of Ionic Liquid Anion Structure on Gas-Ionic Liquid Partition Coefficients of Organic Solutes Using Machine Learning.

This article presents an in-depth investigation into the influence of anionic structures of ionic liquids (ILs) on gas-ionic liquid partition coefficients (log K) of organic solutes in three ILs. While the primary objective was to examine whether there is a relationship between the molecular structure of the IL anion component and log K, additionally it was looked at whether the molecular descriptors of the anion in the relationships encode possible molecular interactions during the miscibility and partitioning in the IL. The research involves the compilation of data series of experimental log K values, where the cation component is constant. Such representative data series were obtained for three solutes─benzene, cyclohexane, and methanol─in three ILs with a uniform cationic component of methylimidazoliums. Using multiple linear regression models enhanced with machine learning techniques, the relationship between anionic structures and log K values was successfully quantified and modeled. Systematically selected molecular descriptors describing the anion structure show that in the case of methanol log K is strongly dependent on hydrogen bonds and Coulomb-dipolar interactions with the anion component, while in the case of benzene and cyclohexane the dispersion forces of the anion component are dominant. The outlier analysis and data interpretation highlight the need for extensive experimental data. The results confirm the initial hypothesis and provide valuable information on the role of the structure of the anionic component in determining the partitioning behavior of organic solutes. This knowledge is important for the design and optimization of ILs for specific applications, particularly as solvents in various industrial processes. The research also provides useful information about molecular interactions taking place in the interfaces of IL and organic additives in complex liquid media such as multicomponent electrolyte solutions, for example in energy storage applications.

Stretchable conducting polymer PEDOT:PSS treated with hard‐cation‐soft‐anion ionic liquid designed from molecular modeling

AbstractPEDOT:PSS, an ionic polymer mixture of positively‐charged poly‐3,4‐ethylenedioxythiophene (PEDOT+) and negatively‐charged poly‐styrenesulfonate (PSS−), is a water‐processable and environmentally‐benign organic semiconductor and electrochemical transistor, which plays a key role in organic (bio)electronic devices. However, pristine PEDOT:PSS films form 10‐to‐30‐nm granular domains, where conducting‐but‐hydrophobic PEDOT‐rich cores are surrounded by hydrophilic‐but‐insulating PSS‐rich shells. Such morphology makes PEDOT:PSS water‐soluble and thermally stable but very poor in conductivity. A tremendous amount of effort has been made to enhance the conductivity of PEDOT:PSS by restoring the extended conduction network of PEDOT. Recently, remarkable ~5000‐fold improvements of conductivity have been achieved by mixing PEDOT:PSS with proper ionic liquids (ILs). In a series of free energy estimations using density functional theory calculation and molecular dynamics simulation, we have demonstrated that the classic hard‐soft acid–base (or cation‐anion) principle of chemistry plays an important role in such improvements. Ion exchange between PEDOT+:PSS− and A+:X− ILs helps PEDOT+ to decouple from PSS− and to grow into large‐scale conducting domains of π‐stacked PEDOT+ decorated by IL anions X−. Thus, the most spontaneous decoupling between soft (hydrophobic) PEDOT+ and hard (hydrophilic) PSS− would be induced by strong interaction with soft anions X− and hard cations A+, respectively. Such hard‐cation‐soft‐anion principles have led us to design ILs containing extremely hydrophilic (i.e., protic) cations and hydrophobic anions. Not only they indeed improve the conductivity of PEDOT:PSS but also enhance its stretchability as well. In summary, our modeling offered molecular‐level insights on the morphological, electrical, and mechanical properties of PEDOT:PSS and a molecular‐interaction‐based enhancement strategy for intrinsically stretchable conductive polymers.

Gold(III) Catalysis in Ionic Liquids: The Case Study of Coumarin Synthesis

AbstractWell‐defined (P,C)‐cyclometalated Au(III) complexes proved to be able to catalyze the synthesis of coumarins by intramolecular hydroarylation of a broad range of aryl propiolates under mild and practical conditions (0.1–2 mol% catalyst, 25–40 °C, 1–24 hours). The use of an ionic liquid as reaction solvent allowed to drastically decrease the amount of Brönsted acid used to unlock the catalyst regeneration step. The effect of the nature of the acid additive and of the ionic liquid anion have been assessed. Preliminary results on the extension of this methodology to the cyclization of aryl propargyl ethers are also presented.

Translational Dynamics of Cations and Anions in Ionic Liquids from NMR Field Cycling Relaxometry: Highlighting the Importance of Heteronuclear Contributions.

NMR field cycling relaxometry is a powerful method for determining the rotational and translational dynamics of ions, molecules, and dissolved particles. This is in particular true for ionic liquids (ILs) in which both ions carry NMR sensitive nuclei. In the IL triethylammonium bis(trifluoromethanesulfonyl)imide ([TEA][NTf2]), there are 1H nuclei at the [TEA]+ cations and 19F nuclei at the [NTf2]- anions. Moreover, the high viscosity of this IL leads to frequency-dependent relaxation rates, leaving the so-called extreme narrowing regime. Both the rotational and the translational dynamics of the constituents of ILs can be obtained by separating the contributions of intra- and intermolecular relaxation rates. In particular, the translational dynamics can be obtained separately by applying the so-called "low-frequency approach" (LFA), utilizing the fact that the change in the total relaxation rates at low frequencies results solely from translational motions. However, for systems containing multiple NMR active nuclei, heteronuclear interactions can also affect their relaxation rates. For [TEA][NTf2], the intermolecular relaxation rate is either the sum of 1H-1H cation-cation and 1H-19F cation-anion interactions or the sum of 19F-19F anion-anion and 19F-1H anion-cation interactions. Due to the lack of available experimental information, the 1H-19F heteronuclear intermolecular contribution has often been neglected in the past, assuming it to be negligible. Employing a suitable set of ILs and by making use of isotopic H/D substitution, we show that the 1H-19F heteronuclear intermolecular contribution in fact cannot be neglected and that the LFA cannot be applied to the total 1H and total 19F relaxation rates.

Molecular dynamics simulation of the interaction between ionic liquid [OPy][BF4] and SO2

Ionic liquids possess novel properties and can efficiently absorb harmful gases, potentially serving as a new type of absorbent. In this study, the binary system of ionic liquid N-octylpyridinium tetrafluoroborate [OPy][BF4] and sulfur dioxide (SO2) has been selected as the research object, and the structure and properties of the system have been studied by molecular dynamics simulation. The interaction between SO2 and ionic liquids is explored by using the radial distribution functions (RDFs), coordination numbers (CNs) and spatial distribution functions (SDFs). The results of microstructures show that due to the strong interaction with anions, SO2 is mostly orderly distributed around the anions of ionic liquids. However, the coordination ability of the polar region of the ionic liquid and SO2 is nearly equivalent to that of the non-polar region. At the same time, it is found that the addition of SO2 enhanced the order degree of the polar and the non-polar regions of ionic liquids, especially on non-polar regions. Through the discussion of the interaction between [OPy][BF4] and SO2, it can be concluded that the mechanism of SO2 absorption by [OPy][BF4] is the combined effect of anions and cations. This study aims to provide new insights for the potential applications of ionic liquids in industrial fields such as petroleum and flue gas desulfurization.

Molecular dynamics simulations of uranyl and plutonyl cations in a task-specific ionic liquid.

Ionic liquids (ILs) are a unique class of solvents with potential applications in advanced separation technologies relevant to the nuclear industry. ILs are salts with low melting points and a wide range of tunable physical properties, such as viscosity, hydrophobiciy, conductivity, and liquidus range. ILs have negligible vapor pressure, are often non-flammable, and can have high thermal stability and a wide electrochemical window, making them attractive for use in separations processes relevant to the nuclear industry. Metal salts generally have a low solubility in ILs; however, by incorporating new functional groups into the IL cation or anion that promote complexation with the metal, the solubility can be greatly increased. One such task-specific ionic liquid (TSIL) is 1-carboxy-N, N, N-trimethylglycine bis(trifluoromethylsulfonyl)imide ([Hbet][Tf2N]) [Nockemann et al., J. Phys. Chem. B 110, 20978-20992 (2006)]. Water, which is detrimental for electrochemical separations, is a common impurity in ILs and can coordinate with actinyl cations, particularly in ILs containing only weakly coordinating components. Understanding the behavior of actinides in TSIL/water mixtures on a molecular level is vital for designing improved separations processes. Classical molecular dynamics simulations of uranyl(VI) and plutonyl(VI) in 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][Tf2N]) with deprotonated Hbet (betaine) and water have been performed to understand the coordination and dynamics of the actinyl cations. We find that betaine is a much stronger ligand than water and prefers to coordinate the metal in a bidentate manner. Potential of mean force simulations yield a relative free energy for betaine coordination of approximately -120 to -90 kJ/mol in mixtures with water. As the amount of betaine coordinated to the actinide increases, the diffusion coefficient of the actinyl cation decreases. Moreover, the betaine ligand is able to bridge between two metal centers, resulting in dimeric complexes with actinide-actinide distances of ∼5Å. Potential of mean force simulations show that these structures are stable, with relative free energies of up to -40 kJ/mol. The crystal structure for [(UO2)2(bet)6(H2O)2][Tf2N]4 shows that the betaine bridges between two uranium atoms to form dimeric complexes similar to those found in our simulations [Nockemann et al. Inorg. Chem. 49, 3351-33601 (2010)].

Boosting cesium retention efficiency with polyoxometalate-ionic liquid composites: Insights into {WO6} octahedral affinity

Commonly used polyoxometalate (POM) adsorbents exhibit high cesium (Cs) adsorption capacity. However, its impotent ability to sequester adsorbates poses a risk of Cs migration in radioactive waste decontamination and disposal. By leveraging the cesium affinity of POMs and the regulatory properties of ionic liquids (ILs), POM-IL composites hold promise for mitigating the risk of cesium migration through efficient adsorption and retention. Herein, we designed two POM-ILs composed of the phosphotungstate anion (PW) and tetrabutylammonium cation (TBA), i.e., the {WO6}-saturated TBA-PW12 and mono-lacunary TBA-PW11, for the capture and retention of aqueous Cs. The composites were then characterized, and the performance and mechanism of Cs uptake were investigated. TBA-PW12 exhibited ∼300 nm aggregate of particles around 20–60 nm. TBA-PW12 retained the Keggin structural features of PW12O403−, which was proven essential for the binding of Cs+. With a retention efficiency of 97.3% in an NH4Cl eluent and a maximum adsorption capacity of 400.9 mg/g at 338 K, TBA-PW12 exhibited superior Cs capture and retention compared to the POM-IL derived from common Cs adsorbent phosphomolybdate. The Cs adsorption onto TBA-PWs achieved equilibrium within 180 min. Cs uptake by TBA-PWs was monolayer chemisorption of Cs+ accompanied by H+ release, and the removal efficiencies stabilized around initial pH 5–10. Due to intense affinity between {WO6} and Cs+, TBA-PW12 efficiently sequestered Cs + through {WO6} octahedra so that the {WO6}-saturated TBA-PW12 presented better Cs uptake performance than the mono-lacunary TBA-PW11. The IL anion [N(C4H9)4]+ provided a composite-water biphasic interface for aqueous Cs adsorption, while retaining the ability of POM cation PW12O403− to form a stable structure with Cs via its affinity to {WO6} octahedra. These findings support the design of POM-IL composites as efficient adsorbents for capturing and retaining Cs, aiding in the decontamination and safe disposal of radioactive waste, thereby minimizing the risk of nuclide leakage into the environment.

Synergistic Dual Activation Catalysis by Saccharin‐Based Ionic Liquids for Diastereoselective Synthesis of Ferrocene‐Appended Furopyranones, Furochromenones, and Benzofuranones

ABSTRACTA practical and straightforward strategy for the synthesis of ferrocene appended furopyranone, furochromenone, and benzofuranone via a metal‐free annulation reaction of imidazolium ylide with enone mediated by saccharin‐based ionic liquid has been reported. The mechanistic studies show an approach through synergistic dual activation of enone and imidazolium ylide via cation and anion of ionic liquid, respectively. This operationally simple protocol offers an easy and rapid access to a library of ferrocene appended furopyranone, furochromenone, and benzofuranone in moderate to good yields through the involvement of a six‐membered transition state.

Influence of some parameters on synthesis processes of triethyl ammonium oleate and triethyl ammonium stearate

Two ionic liquids named triethyl ammonium oleate ([TEA][Oleate] and triethyl ammonium stearate ([TEA][Stearate]) were synthesized from triethyl amine and oleic/stearic acids in water and in ethanol solvents. The synthesized ionic liquids were characterized by FT-IR and NMR spectra to confirm their structure. The influence of some parameters such as structure of ionic liquid anion, solvent, reaction time, reaction temperature, and acid/amine molar ratio on the synthesis processes of triethyl ammonium oleate and triethyl ammonium stearate was investigated. Ethanol was found suitable as a solvent for these processes because it dissolves formed ionic liquids but does not dissolve co-product KCl. In order to shift the equilibrium to increase the ionic liquid yields, an access amount of acids was used. Stearate-based ionic liquid should be synthesized at higher a temperature and longer time than oleic-based ionic liquids.

The Role of Asymmetry of Perfluoro anion in Ionic Liquids: From Basic Physical Properties to the Application in Lithium Batteries

Room-temperature ionic liquids (RTILs) have attracted significant attention as non-volatile, non-flammable electrolytes over the past three decades. While the synthesis of cationic species is relatively well-established through the quaternization reaction of tertiary amines, the synthesis of perfluoro anions is much more difficult, resulting in a more limited variety compared to cations. In this study, we explore the influence of anionic species on both fundamental properties, such as thermal properties and transport properties, and on the performance of lithium-ion batteries, particularly their rate capabilities. Furthermore, we highlight how novel anionic species not only improve the properties of RTILs but also lead to the development of unique electrolyte systems, such as organic ionic plastic crystals and medium-low temperature lithium molten salts. Through our research results, we would like to demonstrate the importance of developing new anionic species from fundamental studies to practical applications in RTILs.

Ionic Liquids-Induced Recovery of the G-Quadruplex DNA Destabilized by Dodine Fungicide.

Dodine is an important surfactant-based chemical fungicide used widely to kill fungi associated with black spot and foliar diseases on several fruit plants, such as apples, pears, peaches, and strawberries. However, the extensive use of dodine depicts the genotoxic effect, which may cause gene-associated diseases. Dodine can destabilize G-quadruplex (G4) DNA, which is one of the key targets for cancer therapy. Hence, finding an eco-friendly medium that can reduce or reverse the destabilization effect of dodine on G4 is important. This study investigates the efficacy of ionic liquids (ILs) containing a 1,1,3,3-tetramethyl guanidinium (TMG) cation with various anions (chloride, acetate, trifluoroacetate, octanoate, and perfluorooctanoate) in restoring the structure and stability of G4 induced by dodine. Our findings demonstrate that all ILs effectively reverse dodine-induced destabilization of G4, with the required concentration varying based on the lipophilicity of IL's anions. Specifically, higher concentrations of TMG-chloride and TMG-acetate are needed compared to TMG-perfluorooctanoate for the same effect. The IL anions remove dodine from G4 binding sites, while the TMG cation's interaction with G4 mitigates the destabilizing effect of dodine. This study indicates that ILs can be an eco-friendly medium for the storage of dodine to reverse the effect of dodine on G4.

Hydrophilicity Dependent Distribution of Water at Ionic Liquids/Metal Interface Monitored by Electrochemical SERS.

The understanding of the interfacial processes is critically important for extending the practical application of ionic liquids, particularly for the role of interfacial water. In the electrochemical system based on ionic liquid electrolytes, small amounts of water at the interface generate a significant change in the electrochemical behaviors of ionic liquids. Therefore, the investigation on the interfacial behavior of water is highly desired in ionic liquids with different anions, water content, and hydrophilicity. Herein, based on the probe strategy, in situ surface enhanced Raman spectroscopy (SERS) combined with electrochemical control (EC-SERS) was developed to investigate the influence of hydrophilicity/hydrophobicity of ionic liquids on the interfacial water. The water-sensitive transformation reaction of 4,4'-dimercaptoazobenzene (DMAB) to para-aminothiophenol (PATP) was employed as a probe reaction for investigating the behavior of interfacial water. The changes of relative SERS intensities of DMAB to PATP served as an indication of the quantity variation of interfacial water. The results show that the transformation reaction efficiencies were critically dependent on the additional water contents, potential, and hydrophilicity of ionic liquids. With a very low molar fraction of additional water (Xw = 0.01), transformation efficiency of DMAB (the amount of interfacial water) followed the sequence of [BMIm]BF4 < [BMIm]PF6 < [BMIm]Tf2N. It was in agreement with the hydrophobicity order of the ionic liquids. With the increase in additional water content, the potential for the full transformation was positively moved, and the efficiency increased significantly. The stronger hydrophobicity allowed more water molecules to migrate to the interface, which was attributed to the difference in interactions between water and the anions of ionic liquids. It demonstrated that the small amount of water tended to gather at the interface in hydrophobic ionic liquids. Compared to traditional cyclic voltammetry, the EC-SERS technique combined with probe reactions is more sensitive to interfacial water. It is anticipated to develop as a promising tool for the investigating water-related issues at interfaces and to provide guidance to screen ionic liquids for practical application.

Superparamagnetic composites of lignin regenerated from ionic liquid solutions for the efficient and selective removal of cationic dyes

Magnetic lignin nanoparticles (MLNs) were prepared by inducing their self-assembly through lignin regeneration in the [N-methyl-2-pyrrolidone][C1–C4 carboxylic acid] ionic liquids ([NMP]ILs), which are low-cost protic ionic liquid. [NMP]ILs are self-assembling solvent that can enhance the adsorption capacity of MLNs to a greater degree than tetrahydrofuran or H2O. Additionally, the anion types of [NMP]IL greatly influence the physiochemical properties of MLNs. The MLNs prepared through self-assembly with [NMP][formate] (MLN/[NMP][For]) exhibited a higher maximum adsorption capacity (134.53 mg/g) than the [NMP]ILs of C2–C4 carboxylate anions. MLN/[NMP][For] demonstrated stable adsorption within a pH range of 6–10 or at high salt concentrations (0.01–0.5 mol/L), retaining over 80 % of its regeneration efficiency after 5 cycles. In addition, MLN/[NMP][For] selectively removed cationic dyes in mixed binary anionic–cationic dye solutions. This work demonstrated the feasibility of preparing magnetic biosorbents with good selectivity and stability though regeneration and by adjusting the anions of ionic liquids.